Latinos accounted for 10 percent of voters across the country this week, ensuring President Barack Obama’s re-election and making a significant impact on statewide and local races.

Election experts said the strong showing sets a milestone for how the Latino vote can affect the outcomes of political contests — and proves the constituency should not be ignored.

Latino clout at the polls also placed a spotlight on the issues they care about most, from the economy to education to immigration. Political analysts said those voters will expect action on those matters.

“Latino voters are a permanent part of the political equation,” said Clarissa Martinez De Castro, a director with the National Council of La Raza in Washington, D.C., which worked to mobilize that community.

“We expect action and leadership on comprehensive immigration reform in 2013,” said Eliseo Medina, international secretary-treasurer of the Service Employees International Union. “To both sides we say: No more excuses, no more obstruction, no more gridlock.”

According to exit-poll results from various sources, Latinos comprised 10 percent of Americans who cast ballots in this election, an increase from about 7 percent in 2008. In California, Latinos made up an estimated 22 percent of the voters in this election cycle.

Polls by media organizations such as CNN, Fox News and ABC reported that more than 70 percent of Latinos voted for Obama, and roughly 27 percent supported Mitt Romney.

Experts said the Republican Party’s stance on immigration, taxes and the economy generally came across as hostile toward Latinos, while the Obama administration’s new initiative to give certain young unauthorized immigrants a two-year reprieve from deportation helped narrow the gap with Latino voters.

Gary Segura, a political-science professor at Stanford University and co-founder of Latino Decisions, said if Romney had garnered as much support from Latinos as John McCain or George W. Bush did in past elections, he might have won the presidency. McCain captured more than 30 percent of the Latino vote, while Bush garnered more than 40 percent in his re-election bid in 2004.

Similar estimates are not available in San Diego County, although campaign activists widely agree that Latinos were a key constituency in this election.

Countywide, about 18 percent of registered voters are Latino, said Carmen Lopez, outreach director for the San Diego County Registrar of Voters. The office is expected to soon release precinct-by-precinct voting data, which experts can use to analyze how different groups — age, race, ethnicity and income — might have voted.

The county’s Latino electorate had grown throughout the year, with nearly 40,000 newly registered voters since January. That accounted for about 40 percent of all new registrants this year, the registrar’s office said.

October saw the largest surge in new Latino voters, with more than 19,000 registering.

Factors contributing to that trend included a sizable number of newly naturalized citizens and the use of voter-registration drives in certain areas of the county, including the “Our Vote, Our Future” campaign that targeted 40 precincts in North County.

In this region and nationwide, advocacy groups said they also worked hard to make sure Latinos not only registered to vote but actually went to the polls.

This election’s formidable Latino turnout will help shape how campaigns are conducted in the future, said Fernando Guerra, a political science professor at Loyola Marymount University in Los Angeles.

In the past, campaigns rarely bothered to court all potential Latino voters, including those with spotty voting records.

“Obama changed that,” he said. “The Obama ground game was colorblind. It went after everyone.”

Guerra said Latinos’ overwhelming support for Democrats this week sent a loud message about their views regarding the Republican Party.

In particular, he said, many Latinos judged candidates through the prism of immigration.

“It’s not that immigration is most important, but that is the issue they know best and internalize. (How can you) illustrate that you are a good guy but you are also willing to deport people and separate families?” Guerra said. “Even second- or third-generation Latinos who are not immigrants themselves see this. If you are anti-immigrant, you are probably also anti-Latino, and you probably wouldn’t give me a fair chance.”

Issues of empathy and trust also played a role in San Diego County, political experts here said.

They are confident that outreach to Latino voters impacted both the San Diego mayoral race and support for Proposition Z, a $2.8 billion bond measure for the San Diego Unified School District that was also the largest school bond offering in California.

The campaign for Proposition Z was focused on Latino voters, said Richard Barrera, a trustee on the San Diego Unified school board.

“Education, year after year, is probably the most important issue to Latino families,” Barrera said. “It’s the reason so many families are working two or three jobs at once — so their kids have a brighter future.”

In the mayoral contest, winner Bob Filner has been receiving kudos from Latino organizers and supporters. They credit his social-media outreach in Spanish, his appearances at Latino community events big and small, and his history of attention to Latinos throughout his political career — from school board member to city councilman to congressman.

Filner spokeswoman Lena’ Lewis said he was unavailable for comment Thursday.

“This election is going to set the tone for the future. If you cannot connect with the Latino community, you will not be elected mayor ... as the population continues to grow,” said San Diego Councilman David Alvarez, who campaigned for Filner.

Another major supporter, the nonprofit Environmental Health & Justice Campaign, targeted dozens of precincts south of Interstate 8 that are predominantly Latino, low-income and highly affected by pollution, lack of public transportation and other infrastructure problems.

“Filner’s candidacy was critically important for our community,” said Diane Takvorian, the group’s executive director. “These are voters who don’t tend to be as well represented, and their influence isn’t acknowledged in most campaigns. They are really the future of our city and our region.”